Sofa



FIG. 1 is a side perspective view of the sofa;

FIG. 2 is a front perspective view of the sofa; and,

FIG. 3 is a back perspective view of the sofa.

The broken lines in FIGS. 1-3 are directed to environment and are for illustrative purposes only. The broken lines form no part of the claimed design. 

CLAIM The ornamental design for a sofa, as shown and described. 